1. Field of the Invention
The present invention relates to a unit curtain wall composed of a plurality of curtain wall units adjustably connected to and hung by fasteners on the exterior structural frame of a building.
2. Description of the Prior Art
Known unit curtain walls are assemblies of curtain wall units, each of which has lateral vertical frame members attached by fasteners to a building skeleton frame. Non-load-bearing curtain wall structure tends to be displaced between building floors when the building is subjected to an earthquake, for example. Since the curtain wall units are mounted individually to the building frame, they are liable to move through different intervals dependent on how they are attached and on their varying inertial forces. Safety requires that the curtain wall units be installed on the building frame by connector arrangements which take up such different displacements of the curtain wall units to cancel out any unwanted impact forces which would otherwise damage the curtain wall units. Conventional connector arrangements however have been quite complex in joining the building skelton frame to the fasteners, and the fasteners to the vertical frame members of the curtain wall units.